Conventionally, a fuel cell power generating system is constructed such that a raw material containing liquid fuel and water as its main ingredients is heated and decomposed by a burner of a reformer to generate hydrogen gas, a fuel cell in which a fuel electrode and an oxygen electrode are disposed on both sides of an electrolyte layer introduces the hydrogen gas generated by the reformer into the fuel electrode to generate electric power and supplies steady electric power to a specified load, a secondary battery supplies required electric power to the load at least at the time of load starting or the time of load variation, and power supply changeover means can switch between power supplied from the fuel cell and power supplied from the secondary battery (JP-A-6-140065). This fuel cell power generating system is constructed such that fuel cell heating means for guiding combustion gas jetted from the burner of the reformer to the fuel cell is provided, and the fuel cell is heated by the fuel cell heating means up to a temperature at which starting is enabled (electric power generation is enabled). Besides, the electrolyte layer is formed of a polymer film having ion conductivity, and methanol is used as the liquid fuel.
In the fuel cell power generating system constructed as stated above, the time that elapses before the fuel cell starts the electric power generation can be greatly shortened by heating the fuel cell to a predetermined temperature by the combustion gas of the burner used at the time of generation of hydrogen in the reformer, so that the power generation efficiency of the fuel cell can be improved. Besides, since the power supply from the secondary battery can be reduced by this, the number of secondary batteries can be decreased, and the compact and lightweight fuel cell power generating system can be obtained.
However, in the conventional fuel cell power generating system disclosed in JP-A-6-140065, since the raw material of the fuel gas supplied to the fuel cell is methanol, if this system is mounted in an automobile, there has been a disadvantage that refueling can not be carried out in a normal gasoline station.
Besides, in the conventional fuel cell power generating system, since the working temperature of the fuel cell is relatively low, there has been a problem that unless methanol is supplied to the fuel cell after it is completely reformed into H2 (hydrogen gas) by the reformer, the power generation efficiency of the fuel cell is lowered.
Further, in the conventional fuel cell power generating system, since the electrolyte layer is formed of the polymer film, there has been a problem that there is a fear that CO (carbon monoxide) is exhausted from the power generating cell, and the treatment of the carbon monoxide is troublesome.